Spark-plug.



D. M. TUTTLE.

SPARK PLUG.

APPLIUATION FILED 1320.6, 1907.

Patented Aug. so, 1910.

gm z wwv DANIEL IVI. T'UTTLE, 0F CANASTOTA, NEW YORK.

SPARK-PLUG.

essere.

Specification of Letters Patent. Application sled December e, 1907.

Patented Aug. 30, 1910. Serial No. 405,450.

To all whom 'it may concern: y

Be it known that I, DANIEL M. TU'r'rLn, of Canastota, in the county ofMadison, in the State of N ew York, have invented new and usefulimprovements in Spark-Plugs, of which lthe following, taken inconnection with the accompanying drawings, is a full, clear, and exactdescription.

This invention relates to certain improvements'in spark plugs for gasengines. These spark plugs are made as separate articles of manufactureand are screwed or otherwise secured to the cylinder so as to bring thespark terminals in the explosion chamber of the cylinder.

In the operation of gas engines, and particularly the liquid hydrocarbontype, it frequently happens that the explosive mixture which isintroduced into the explosion chamber is improperly mixed vandununiformly distributed so that someV parts of the mixture may becorrectly proportioned while other parts will be too rich or contain anexcess of air and furthermore it is 'customary in the spark plugsheretofore employed to use a single spark gap which, of course, isnecessarily located at one'xed point in the explosion chamber and it notinfrequently happens that the portion of the mixture which 1s ein theimmediate vicinity of the sparking terminals is too weak to be ignitedby the spark thereby causing the engine to miss firing at regularLvcycles of operation. Furthermore where a single spark gap is employedthe intensity of the spark particuarly under a weak electric current'maybe insucient to ignite the explosive mixture thus producing the sameresult of missing lire at regular cycles of operation.

The object of my invention is to overcome these diliiculties byproviding the spark plug with a plurality of spark gaps or arcs forv thepurpose of not only intensifying the spark at each break of the circuitbut also to bring the arcs in different localities of the explosionchamber so as to increase the probability of ignition at each cycle of0peration of the engine and thereby reduce the liability of misfiring.

' Another object is to render the electrodes self-cleaning by allowingone of them to ro-y tate relatively to the others.

Other objects and uses relating to the speciic construction of the sparkplug will .be brought 4out in the following description.

In the drawings Figure 1 is an elevation, partly in section, of one formof spark plug for carrying out the objects stated. Fig. 2 is a sectionalview taken on line 2 2, Fig. l. Fig. 3 is an inverted en d view of thespark plug seen in Figs. l and 2. Fig. 4 is an elevation similar to Fig.l of a modified form vof spark plug also adapted to carry out the sameobjects. Fig. 5 is a sectional view taken on line 5 5, Fig. 4:. Fig. 6is an inverted end view of the spark plug seen in Figs. 4 and 5.

The device shown in Figs. 1, 2 and 3 comprises essentially a tubularmetallic sleeve l havin@f a spark terminal. or electrode' 2 a tu ularbushing 3 of insulating material passing through the sleeve 1 anelectric conductor 4 passing centrally through the provided with aterminal or electrode 5 and a conductor 6 interposed between theelectrodes or termi als Q and 5 forming intervening spark gaps 7 and Thesleeve 1 is provided at one end with a male thread 9 and at its oppositeend with a female thread 10 the male thread 9 being adapted to bescrewed into the cylinder of the engine, not shown, while the femalethread l0 receives a threaded cap or follower ll having a centralopening 12 therethrough for the reception of the insulating bushing 3said sleeve 1 being also provided with an annular shoulder 13-substantially midway between its ends forming a seat for a suitablepacking or buffer l3 The insulating bushing 3 is bushing 3 and lpreferably made of porcelain or equivalent material and is inserted intothe sleevel it being provided with an annular enlargement M forengagement with the packing 13 to limit the inward movement of thebushing relatively to the sleeve 1 said enlargement bein tween the endsof the sleeve an held against outward movement by the follower 11 theinner end of which is engaged with the annular enlargement 14 Thisinsulating bushing 3 serves to electrically located beinsulate theconductor #4.- from the sleeve 1- which latter is in electricalconnection with the frame or cylinder of the engine and may beelectrically connected in any well known manner to a source of electricenergy not shown. The electrode w-2- is secured to and in electricalconnection with the sleeve 1 as best shown in Fig. l and extends somedistance beyond and is insulated from the elect-rode -5, both of whichelectrodes protrude some distance nwardly from the inner ends of thesleeve -l and bushing -3-. so that the intervening space between theelectrodes 2 and 5 is wholly within the explosion chamber of thecylinder, not shown. This insulating bushing 3eis provided with acentral lengthwise opening -15-- extending therethrough from end to end,the inner end of said opening being enlarged forming an annular shoulderor abutment -16 having a corresponding annular enlargement -17 on theadjacent portion of the conductor L1-1 said annular enlargement beingprovided with a yielding buffer or packing -18- lying next to theshoulder -16- to enable the conductor 4- to be secured in place withoutliability of breaking the insulator -3-. The conductor lconsists, inthis instance, of a metal rod or stem extending entirely through theopening -15- and beyond the opposite ends of the insulator #8, the innerend forming the electrode -wwhile the outer end is threaded to receive aclamping nut -19, said nut coacting with a metallic cap 20- on the outerend of the insulating sleeve -3 to receive between them one of the wiresof the electric sparking circuit. The conductor -6- consists of aU-shape electric conducting bar -21- and a rotary electric conductingsleeve or electrodes -22, the U-shape bar 2lhaving the terminal ends ofits arms offset toward each other and seated in sockets -23- in oppositesides of the inner ends of the insulating bushing -3- as best seen inFig. 2 while the intermediate portion or base of said U- shape bartogether with the rotary electrode 22- which is mounted thereon areinterposed between the terminal ends of the conductors or electrodes -2-and -5- leaving sucient intervening space to form the spark gaps 7 and-8- said sleeve being free to rotate by the action of the explodinggases and it is, therefore, self-cleaning. The conducting sleeve orelectrode -22- and adjacent portion of the bar 2lare in line with theelectrode -5- and serve as a conductor for the current arcing across thegaps -7- and -8 so as to produce in this instance two sparks one at thegap -7- and another at the gap 8 in diteient arts of the explosionchamber although it 1s evident thatthe number of gaps may be multipliedand otherwise located if desired without departing from the spirit ofthis invention.

The spark plug shown in Figs-4 to 6 inclusive is substantially like thatshown in Figs. l to 3 inclusive except that I have* shown a tubularmetallic sleeve #25-- as provided with pendent arms -26- in which issecured a cross pin or bearing -27- and upon this pin is mounted arotary sleeve -28- of insulating material such as porcelain spaced apartsome distance from the lower end of the insulating bushing -8-. Thecentral-.portion of this insulating sleeve -28- is smaller than its endsand upon it is mounted an electric conducting ring or electrode -29-,adapted to rotate with or upon the insulator -28--. This conducting ringor electrode 29- is in line with and spaced apart a slight distance fromthe electrode 5 forming an intervening spark gap -30-. An additionalspark terminal or electrode' -31- is secured to and in electricalconnection to the sleeve -25- and has its inner end terminating a shortdistance from the inner side of the conducting ring -29- forming anintervening spark gap -32 at the side of the ring -29- diametricallyopposite the spark gap -30- thereby forming two spark gaps both of whichare always available for producing a spark and igniting the explosivemixture at each break of the sparking circuit in the manner well known,the insulator sleeve n28 and ring -29-f being free to rotate on the partw27- by the action of the exploding gases so as to make the electrodesself-cleaning. By introducing these two or a plurality of spark gaps inthe manner described the electrical resistance is increased. by reasonof the double arc thereby increasing the intensity of the spark atbothgaps and at the same time multiplying the sparks and locating them indifferent positions in the explosion chamber so as to insure a moreperfect explosion at each cycle of operation of the l engine.

What I claim is:

1. Ak spark plug comprising two spark terminals insulated from eachother and held a fixed distance l'apart forming an intervening air gap,a support extending across the air gap and spaced apart from bothterminals, and an electric conductor encircling said support in linewith and rotatable relatively to the terminals.

`2. A spark plug com rising spark ter minals insulated from eac i otherand spaced apart forming an intervening spark gap, a support extendingacrosssaid gap apart from both terminals, and a ring of elec tricconducting material rotatable around said support inline with theterminals but spaced apart therefrom.

3. A spark plug comprising two spark terminals insulated from each otherand spaced apart forming an intervening spark gap, a rotary insulatorextending' across the spark gap, a support for the insulator, and

an electric conducting ring encircling the 10 insulator in line with butspaced apart from the terminals. In Witness whereof l have hereunto setmy hand this 29th day of November 1907. DANIEL M. TUTTLEi. Witnesses:

H. P. DENIsoN, M. M. NOTT.

